In measurement- and control technology, so-called mass air flow meters (LMM, MAF) or mass air flow sensors (LMS) are used for determining the mass flow of air. An important area of use of such sensors lies in the field of the control of combustion processes, in particular in internal combustion engines, which depend significantly on the molar quantity of supplied atmospheric oxygen. Generic mass air flow meters therefore frequently come into use particularly in automobile, gas turbine and calorific value technology.
In engine management, such measuring sensors are used in particular in order to adjust—for example in the case of modern Otto or diesel engines—the amount of fuel to be injected into the intake tract or combustion chamber of the engine to the volume flow of the supplied fresh air. From the point of view of measurement accuracy, the stabilizing of the drawn-in air proves here especially to be a critical requirement for the subsequent measuring section. For this reason, the prior art comprises for example so-called Karman vortex mass air flow meters, which aim for a uniform flow speed by means of a honeycomb grid arranged at the inlet thereof.
A chronologically particularly high-resolution measurement, on the other hand, can be produced according to the prior art by way of thermal anemometry by means of so-called hot film mass air flow meters (HFM), which in vehicle internal combustion engines are usually arranged behind a possible air filter in the intake manifold. The invention is therefore based on the problem of providing an air filter which within the intake tract of an internal combustion engine is able to contribute to the stabilizing of the measurement signal of a downstream mass air flow meter. In addition, the invention sets the problem of providing an internal combustion engine which has been improved in a corresponding manner, in particular in the form of a combustion motor for a motor vehicle.